Efforts by individuals, couples, health care providers and policymakers to achieve the Healthy People 2010 goal of reducing the nation's rate of unintended pregnancy are hampered by incomplete information about its incidence, by inadequate understanding of the factors driving unintended pregnancy rate trends and differences across sociodemographic groups, and by lack of easy-to-use tools for regular monitoring of these trends and differences. In response to these deficits, this project would: 1. Estimate up-to-date levels of total and unintended pregnancy (the first since 2001) for the United States and key sociodemographic subgroups, including age, marriage and union status, poverty status race/ethnicity, education, parity, religious affiliation, and (for the most recent period) immigration status. National data on pregnancy intendedness are collected by the National Survey of Family Growth (NSFG), but these data are substantially incomplete with regard to the one-fifth of pregnancies that end in abortion. We would fill this gap with data collected (with independent funding) from a national census of abortion providers and a nationally representative sample of women having abortions, and using estimation methodologies developed by Guttmacher researchers. 2. Analyze the relative contributions of key intermediate factors to differences in unintended pregnancy rates over time and across sociodemographic subgroups. We would ascertain the role of these factors - population composition, sexual activity, fecundity, desire for childbearing, contraceptive use and effectiveness) - in accounting for time trends 1987-2009 and for differences across population groups. In the process of doing so, we will use multiple approaches to measurement (measures based on one point in time vs. across a longer period of exposure) and to analysis (descriptive comparative analysis, decomposition and standardization techniques and multivariate analyses) in order to identify the most stable results. 3. Estimate up-to-date contraceptive use-failure rates corrected for underreporting of induced abortion, in order to inform and counsel sexually active couples who want to avoid becoming pregnant and to determine the possible impact of changes in method use-effectiveness on unintended pregnancy rate trends and differences. 4. Develop a tool based on NSFG survey data alone for monitoring population trends in unintended pregnancy risk and protection that can be used as a proxy for unintended pregnancy rates themselves, but can be implemented more frequently and less expensively and thus supplement the calculation of actual rates, which remain necessary but which can only be done at periodic intervals of five or more years. PUBLIC HEALTH RELEVANCE: Public health efforts to reach the Healthy People 2010 goal to reduce unintended pregnancy from its current proportion of roughly half to 30 percent of all pregnancies, to monitor progress in addressing the negative health and social consequences of mistimed or unwanted births, and to reduce the need for induced abortion are hindered by the lack of accurate and regular measures of unintended pregnancy that adjust for abortion underreporting in the primary monitoring tool (the National Survey of Family Growth). Accurate, ongoing and frequent measures are now especially needed to monitor and understand unintended pregnancy trends and subgroup differences, since recently published data indicate possible changes in birth and abortion rate trends. Such measures are also needed for policy and programs to appropriately respond to the growing recognition that unintended pregnancy and its sequelae are issues not only for adolescents and unmarried women, but also for adult and for ever-married women, who now account for a substantial proportion of unintended pregnancies and abortions.